Batteries Definition and 456 Threads

Question 1: Why use an iron core armature? I took an old electric motor apart to study it. I noticed the armature has windings around an iron core. Iron is used to concentrate the magnetic flux. But iron is also attracted to the electromagnets used to repell the armature windings! It seems to...

I have 4 of those big 6V batteries used mostly in flashlights. The batteries are almost dead and I really don't want to break the bank buying new ones. Can I just hook them up to my 9V battery charger (in parallel) and charge them? Will they hold a charge again? Will they explode?

I have a homework problem that asks me to find the charging capacity of a battery. I wasn't sure how to find this or what equation to use. I wasn't sure if the charging capacity was an equivalent to the capacitance. Can someone point me in the right direction? Note: I am given it's a 12 V...

Nickel-Cadmium (nicad) batteries have the strange tendency to stop working unless they are completely drained then completely recharged. If the batteries are fully charged, drained maybe 20% then charged again, and this is repeated several times, the batteries simply don't work any more. If the...

E=MC squared? Assuming this is correct which I assume it is, a rechargeable battery should weigh more when charged, compared to un charged, has anybody actually put this to the test?

Two questions here that I hope you can help with. 1) If an electrical current flows because of the attraction and repulsion between electrons and the terminals, do the electrons actually go though the battery? 2) I know that the battery does not put electrons into the circuit so, if the...